The material is different. Raw flour is generally made of potato flour and corn flour, while starch is made of many materials, such as sweet potato flour, Ge Fen, cassava flour and so on.

Raw flour usually appears in the recipes of Hongkong and Taiwan Province. It refers to an ingredient used for sizing and thickening. The name of starch generally appears in Chinese food and is used for thickening and sizing.

1. Starch is polymerized from glucose molecules, and glucose is the most common storage form of carbohydrates in cells. [1] starch, also known as starch in catering industry, has the general formula of (C6H 12O6) n, and when it is hydrolyzed into disaccharide, it is maltose with the chemical formula of c12h22o1kloc-0/. After complete hydrolysis, monosaccharide (glucose) was obtained with the chemical formula of C6H65438. .

2. Starch includes amylose and amylopectin. The former is a spiral structure without branches; The latter consists of 24~30 glucose residues connected end to end by α- 1, 4- glycosidic bond, and the branch is α- 1, 6- glycosidic bond. Amylose is blue when exposed to iodine, while amylopectin is purple when exposed to iodine.

3. This is not a chemical reaction between starch and iodine, resulting in interaction, but the central hole of the starch spiral can just accommodate iodine molecules, and they form a blue-black compound through van der Waals force.

4. The experiment proves that iodine molecule alone can't make starch blue, but it is actually iodine molecule ion (I3) that makes starch blue. Starch is a nutrient stored in plants, stored in seeds and tubers, and the starch content in various plants is very high.